This invention relates to a therapeutic instrument known as a laryngoscope used to visualize the laryngeal area of the human body.
Laryngoscopes are routinely used to facilitate endotracheal intubation such as during surgery to permit the patient to breathe and/or to administer anesthesia. In addition, laryngoscopes are utilized to displace the tongue and epiglottis thereby to permit direct visualization of the glottis through the mouth opening.
The standard method for performing intubation involves placing the patient in a supine position, tilting the head backwards as far as possible and distending the lower jaw to open the mouth widely. A rigid blade, which can be straight or slightly curved, then is inserted through the mouth into the throat passageway to displace the tongue and epiglottis thereby to expose the glottis. Thereafter, the desired visual observation can be achieved, the anesthetic can be applied and/or the mechanical ventilation may be effected. When utilized, the endotracheal tube is inserted either orally or transnasally and passed along the laryngoscope blade into the glottis.
Endotracheal intubation performed in the foregoing manner may cause undesirable physiological reflexes and require the use of an anesthetic. The use of such blades frequently requires contact with the upper teeth so that the blade is pivoted about the edge of these teeth during use. This frequently results in the teeth being broken or injured. In addition, the size and shape of the tracheal passage varies with the patient, particularly, if the patient is afflicted with a disease that affects the trachea. Thus, with a laryngoscope having a rigid blade of fixed size and shape, possible injury to the patient is increased as the size and shape of the trachea varies from patient to patient. Although transnasal intubation minimizes the possible injury to teeth during endotracheal intubation, it has certain disadvantages. The reverse curve of the passage used to enter the larynx and trachea from the nose is difficult to traverse safely with conventional endoscopes due to their limited degree of distal articulation. Accordingly, it would be desirable to provide a means for effecting endotracheal intubation which minimizes or eliminates the drawbacks associated with conventional laryngoscopes and which are more convenient to use than presently available nasopharyngoscopes.